The problem was detected shortly after Galileo took an image of Jupiter and its major moons from 36 million kilometers (22 million miles) away. After taking the three images required for a color photograph to be produced, the tape recorder used to store the data was commanded to rewind. Data received from Galileo suggest the tape recorder did not stop as expected after rewinding.

Galileo engineers have commanded the tape recorder to a standby mode while they investigate further, said Galileo Project Manager William J. O'Neil of NASA's Jet Propulsion Laboratory (JPL), Pasadena, CA. Project engineers are proceeding slowly and cautiously to understand the problem, according to O'Neil, and are avoiding sending unnecessary commands to the spacecraft. In addition to analyzing spacecraft telemetry, engineers are working with an identical tape recorder in a laboratory spacecraft mockup on the ground.

Project officials say a week or more may be required for the problem to be isolated or well-understood, but that the spacecraft remains otherwise healthy and in contact with controllers on Earth. "The next scheduled spacecraft operation that we need to perform is a routine thruster flushing in about two weeks," said O'Neil. "We want to take the time in the interim to understand this problem in detail."